One of the most carcinogenic (cancer causing) thing you can eat is burnt meat. Yes, that crispy outside of your steak is as likely to give you cancer than anything else you put in your mouth.
It makes sense if you think about it. Meat is made of exactly the same proteins and chemicals as our bodies. Cook the meat and they start to break down creating reactive molecules very similar to healthy ones in our bodies. The nasties in this case are heterocyclic amines (HCAs) – shown to cause cancer in rats and listed as a carcinogen by the US government in 2005.
However burnt meat doesn’t contain much of this material so you’d have to love your BBQ a lot to worry. In fact, on a summer day, the sun could be more carcinogenic than the lunch.